Pump



April 5, 1960 G. s. DLUGOS 2,931,302

PUMP

Filed April 15, 1957 fnz/enzgr" Gerald 5. $11505 United States Patent PUB E Gerald S. Dlugos, Par-ma, Ohio, assignor to Borg-Warner Corporation, Chicago, 1114., a corporation of Illinois Application April 15, 1957, Serial No. 652,735

2 Claims. (Cl. 1034) This invention relates to gear pump assemblies and more particularly to assemblies incorporating gear pumps of the pressure loaded variety.

More specifically, this invention relates to a pump assembly having a plurality of separate pumping elements with a common pressure loading bushing or end plate means associated therewith. Therefore, the principal object of this invention is the provision of a pump assembly of the pressure loaded variety having a plurality of pumping elements and a common pressure loading bushing or end plate means associated-therewith.

The pump assembly of this invention is provided with a plurality of pumping elements each separated by axially movable spacer means and is constructed and arranged to have at least one pumping means axially movable, so that a single pressure loaded bushing or end plate means is elfective to provide efiective pressure seats with the side faces of each of the pumping elements.

Therefore, another object of this invention is the provision of a pump assembly having axially movable spacer means between pumping elements, at least one axially movable pumping means and a single pressure loaded bushing or end plate means.

Other objects and features of this invention will become apparent from the following description when taken with the accompanying drawing, in which:

Figure 1 is a plan view of the pump assembly of this invention, with some parts shown in section; and

Figure 2 is a sectional view of the pump assembly of this invention taken on line 22 of Figure 1 and looking in the direction of the arrows.

Referring now to the drawing, and in particular to Figure 2, the pump assembly, generally identified by P, comprises a housing H including a body and a cover 11 suitably secured together by means such as bolts or the like (not shown).

The body 10 is bored to provide overlapping or intersecting, parallel, cylindrical cavities 12 and 13 to receive, in spaced relation, pairs of gears 14, 15 and 16, 17, each pair meshing in the overlapping area. The pairs of gears may be of difierent Widths, providing different pumping capacities, or of the same width and pumping capacity, without departing from the spirit of the inventron.

Bores 18 and 19, for purposes to be described, are provided in the body and are concentric with each other and the cavity 12, the bore 18 being smaller in diameter than the bore 19. A smaller bore 20 is provided in the body intersecting and concentric with the bore 13.

The cover 11 is provided with bores 21 and 22, for purposes to be described, which intersect the cavity 12 and are concentric with each other and the cavity 12, and with a cavity 23 intersecting and concentric with the cavity 13.

The gear 14 comprises a driving gear and is, as illus trated, formed integral with a drive shaft 24 terminating at its opposite ends in splined portions 25. The gear 14 could be drivingly afixed to'the shaft 24 in other suitable ways without departing from the spirit of this invention. The shaft 24 is provided with a radial hole 27 to receive a pin 28 received in an axial slot 29 formed in the hub portion of the gear 16, thereby providing a driving connection between the shaft and the gear While allowing for axial movement of the gear.

The gear 15 is, as illustrated, formed integral with a stub shaft 30 which receives, in spaced relation, the gear 17 having a sliding fit therewith. As in the case of the gear 14, the gear 15 could be suitably allixed to the shaft 30, instead of being made integral therewith, without departing from the spirit of this invention. The shaft 30 is hollow, so as to allow the passage of leakage fluid therethrough.

The shaft 24 is journaled in bushing means 31 and 32, each of which has a journal portion extending into the bores 18 and 21, respectively, and the shaft 36 is journaled in bushing means 33 and 34, each of which has a journaled portion extending into the bores 29 and 23, respectively. The bushing means 31 and 33 define the left bushing or end plate means for the gears 14 and 15 and are substantially fixed in their operative positions. The bushing means 32 and 34 define the right bushing or end plate means for the gears 16 and 17 and are axially movable and adapted to be pressure loaded in a manner to be described.

To separate the pairs of intermeshing gears and to thereby define spaced pumping chambers in which the pairs of gears may perform their fluid pressure function, there is provided bearing spacers 35 and 36 having central bores 37 and 38, respectively, within which the shafts 24 and 30 may rotate without interference. The spacers 35 and 36, which are slidable with regard to the walls of the cavities 12 and 13, define the right bushing or end plates means for the gears 14 and 15 and the left bushing or end plate means for the gears 16 and 17.

Inlet passages 39 and 40 are provided in the body 10 leading to the spaced pairs of gears, namely 14, 15 and 16, 17, respectively, and outlet passages 41a and 41b terminating in a common outlet passage 41 is provided for the assembly. The passages 39, 40 and 41 all terminate in internally threaded portions to which may be afiixed suitable conduits, hoses, or the like.

As illustrated, the bushing means 32 and 34 have end walls 42 and 43 spaced from the end walls 44 and 45 defining the cavities 12 and 13, so that annular intersecting chambers 46 and 47 are defined therebetween. The end walls 44 and 45 are sometimes referred to as pressure motive surfaces, and the chambers 46 and 47 are sometimes referred to as pressure motive chambers. A thin washer member 48 is disposed against the walls 44 and 45, so as to retain O-ring seals 49 and 56 surrounding the journal portions of the bushings 32 and 34 in their effective positions. Also, an O-ring seal 51 is disposed between the juncture of the body and cover 10 and 11, respectively, of the housing H. These 0ring seals are necessary to prevent the leakage of fiuid from the chambers 46 and 47. The bushing means 32 and 34 are provided with open-ended cavities 52 and 53, respectively to receive coil springs 54 and 55 compressed between the bottoms of their respective cavities and the washer 48.

Means in the form of a passage 56 (see Figure 2), delined by the bushing members 32 and 34, and the body 10, communicating the outlet 41 and the intersecting chambers 46 and 47, is provided for conveying high pressure fluid to the chambers 46 and 47.

As will be obvious, high pressure fluid in the chambers 46 and 47 will urge the bushings 32 and 34 to the left, thereby also urging the gears 16 and 17 and the bearing spacers 35 and 36 to the left. The result is to provide a seal between thebnshing means 31, 33,35 and 36 and the side faces of the gears 14 and 15, and'a' seal between the bushing means 35, 36, 32 and '34 and the side faces of the gears ldand 1?, andas obvious, the sealing force will increase as'the outputpressure from the assemblyincreases; Such'fluid pressure .seals substantially 7 reduce or prevent Eithe by-passingof fluid from. dischargeiback e-toinlet across the faces of the gears, and therebyincrease the efliciency 'of the pump assembly. The springsjSZ and 53 provide an initial loading force, so that the bushing means willbeurged into sealing engagement with their respectivegears upon the starting of the operation ofthe device. a Y

Relief recesses, such-as 57, are provided in'the bushing means,- as illustrated; and are in communication with a zone of low pressure by means-of passages 58 in' the bushings; The function of then-relief recesses is the same as set forth in Lauck et al. Patent No:2,420,'622.

Drive Couplings 59 and 60 and associated shaft sealinga a cup-like member adapted to receive a shaft, The shaft sealing means 61, form no part of this invention, and v are substantially'the same construction as shown in the aforesaid Laucket al. patent;

The pump assembly just described is especially adaptable for conveying fiuid'underpres'sure' from two sources 7 to one utilization device, or, to draw fluid from two utilization devices andconvey it to a single'sump; I I

- While this vinvention has been described with reference to one specific embodiment,- it is" tobe understood that this is byway of illustration and not by way of limitation and the claimsappended hereto are to be construedas broadly as the prior art will permit. a

I claim: g 1. In a pump assembly, thecombination of a housing having a pair of'spac'ed wall means, means defining a cavity in said housing between said wall means, means definingta'pair of pumping chambers in said cavity, said pumping chambers beingin substantially: aligned rela-f tion between saidwall means, an inlet andan outlet for each pumping chamber, said ,outlets terminating in a common port, pumping elements in each pumping chamber, means including a shaft to provide a driving means for said pumping elements, means includinga pin connection for drivingly connecting one portion of one of said pumping elements to said shaft for axial movement,

relative thereto, said defining means including a fixed bushing means disposed between one of said wall means and the pumping elements adjacent-thereto-and axially movable bearing spacer means disposed between the adiacent pumping elements and axially 1 means disposed between the other of said'wallmeans and the pumpingielements adjacent thereto, and means to. i

movable bushing pressure load said bushing means to' axially. move, said bushing means, said pumping elements, and said spacer means in packed relation against said one wall means and thereby provide pumping seals between said chambeidefining means and the adjacentside faces of said pumping elements. t 1 r 2. Inxa pump assembly, the combination ofa housing having arpair of spaced wall means, means defining a cavity in said housing between said wall means, means defining a pair of pumping chambers in said cavity, said pumping chambers, being 'in substantially aligned relation between said wall means, an inlet and an outlet for each pumping chamber, pumping elements comprising pairs of intermeshing external gears in each pumping chamber, a shaft for providing a driving means for s'aidpumping elernents, means for drivingly connecting oneof eachpair of gears to said shaft, one'of said drivingly connected gears having a pin connection with said shaft and being adapted for axial movement'relative thereto, said defining means including a fixed bushingjmeans received in said a cavity between oneiof said wallmeans andthepumping elements adjacent thereto and aiiially movable bearing spacer means disposed between adjacent pumping elements and axially movable bushing means-disposed bements adjacent thereto;'means defining a pressure motive chamber including said other wall means and a surface on said axially movable bushing means, and means to communicate output pressure to said pressure motive chamber. to' urge said axially movable bushing means,

said pumping elements, said bearing spacer means, andt said fixed bushing means in packed relation against said one wall means to provide pumping seals between said chamber defining means, and the adjacent side faces: of said pumping elements.

References (Sitedin the file of this patent UNITED STATESPATENTS 2,009,137. Kleckner July 23,1935 2,312,886 Ellinwood Mar. 2, 1943 2,382,042 Etnyre' Aug. 14; 1945 2,412,588 Lauck' Dec. 17, 1946 2,490,115 7 Clarke .2 Dec. 6, 1949 2,665,637 Lauck Jan. 12, 1954 2,665,638 Lauck Jan. 12, 1954 2,845,873 v Lapsley Aug. 5, 1958 FOREIGN PATENTS 7 609,108 Great Britain Sep 24, 1948 716,039 Germany Ian. 12, 1942 

